Summertime sadness...

One of the clearest differences between depression and melancholy is that depression is an emotional state of resignation, whereas melancholy is not. When we feel depressed we feel unmotivated, unable to complete even the simplest task and unable to see any way forward. It is a pessimistic state that involves pain. By contrast, melancholy is not such a debilitating mood, rather it involves the pleasure of reflection and contemplation of things we love and long for, so that the hope of having them adds a touch of sweetness that makes melancholy bearable (while misery is not). Its reflective or thoughtful aspect also makes it somehow productive. Melancholy is something we even desire from time to time, for it provides an opportunity for indulgent self-reflection. We enjoy this time out for reflection, but the pleasure is also connected to recollecting that which we long for, where this reflective element can be even exhilarating or uplifting.

- from Melancholy as an Aesthetic Emotion by Emily Brady and Arto Haapala

("Melancholy" 1894, Edvard Munch)